Matching Design For Air Conditioning System Of Electric Vehicle

With the global warming and energy crisis becoming increasingly fierce, the traditional gasoline-powered automobiles polluted the environment heavily dueing to its large amounts of consumption of fossil oil. However, the electric vehicles are not harmful to the environment and their source of power—electric energy could be got through many ways. Whatsmore, the cost of the electric energy is lower than the ones of the petrol. Thus, in order to ease the pressure of the petrol-consuming and protect the environment, the replacement of the electric vehicles for the petrol-driven ones will be the right choice.It is necessary for the electric vehicles to provide a comfortable environment for the user. Thus, the air-conditioner is indispensable. That how to install the air-conditioner and reduce its affection on the dynamic performance and driving range of the electric vehicles makes the development and matching design of the air-conditioner system for the electric vehicles an important task of developing the electric vehicles.This paper firstly makes a systematic description of the development of the electric air-conditioning system home and abroad and makes a comparison of the electric air-conditioning system and the traditional ones. It also analyzes the latest development of the electric air-conditioning system. After analyzing the program of the electric air-conditioning system home and abroad, a proper solution for the electric air-conditioning system is raised in this paper. Afterwards, this paper makes a lectotype design of the main parts of the electric air-conditioning system, such as motor compressor, evaporimeter, condenser and the expansion valve. And it also analyzes the heat dissipating capacity of the battery and decides the scheme and matching parameter of the cooling system of the battery.Based on the principle of the antomative air conditioning, this paper makes a matching calculation for the parameter of the electric air-conditioning system. On the basis of the service environment of the electric air-conditioning system, the thermal cycle pressure-enthalpy diagram and the operation conditions of the system are decided, and the matching parameter of the system is calculated. The Coolant System driven by motor compressor could be adopted in the refrigeration of the electric air-conditioning system. While for the heating, as there is no waste heat from the engine, other heating method could be adopted, such as electric heater. As the power battery is sensitive to the temperature, no matter adopting the air-cooled or the liquid-cooled battery cool system, the cold source should be provided by the air-conditioning system. The comfortableness of the passenger compartment, the cooling of the battery and other restricting conditions such as the available power should be all took into consideration for the integrated match of the electric air-conditioning system. Because of the battery's sensitiveness of the temperature, usually, the battery efficiency would be affected under the low temperature while the battery life would be shorted under the high temperature. Thus, under the complicated working model and condition, in order to make the battery maintain or approach the best working temperature, it is very important to make suitable system design and control the parameter except for the design for the cooling structure of the battery.Through the bench test, the charge amount of the refrigerating fluid for the electric air-conditioning system is decided, the parameter of the expansion valve and the filling quantity of the refrigeration oil of the motor compressor. At last, the refrigeration effect of the air- conditioning system is proved through the environment simulation.